This invention relates generally to a hermetically-sealed collapsible terrarium assembly which includes a replaceable dome that is inflatable to assume a desired configuration, and more particularly to a terrarium of the type which is inflated with an inert gas or other controlled atmosphere.
The traditional terrarium is a fully enclosed, small container, wholly or predominantly made of glass or other rigid transparent material, the terrarium being adapted for the indoor cultivation of moisture-loving plants. The earliest form, known as a Wardian case, was invented by an English botanist in the 19th century, the case being constituted by a box-like glass dome fitted over a metal, earthenware or wooden base serving as a pot for growing living plants. Normally, moisture from an exposed plant is dissipated into the atmosphere through transpiration, so that the plant must be watered at frequent intervals, but in a terrarium the loss of moisture is slight and it is not necessary to replenish the water except occasionally.
Because of the growing popularity of terrariums, they are now mass-produced and commercially available in rigid, transparent plastic form. The terrarium consists of a plastic base having a pot formation for receiving plant soil and a plastic dome or shell which fits over the base. Plastic terrariums come in a range of sizes, and the larger ones are not only fairly expensive, but because of their size they are not easily stored when not in use, particularly in a small apartment dwelling.
But a more important drawback of existing types of rigid glass or plastic terrariums is that they are not hermetically sealed, so that even though these enclosed terrariums reduced the loss of moisture, they are incapable of maintaining an atmosphere of high humidity of the type necessary, for example, in promoting the growth of certain exotic or tropical plants. It is for this reason that when bell jars are used as terrariums, it is the present practice to apply grease or oil to the rim of the jar in order to improve the seal thereof.
With a view toward overcoming the drawbacks of existing types of rigid terrariums, there is disclosed in the above-identified copending patent application, whose entire disclosure is incorporated herein by reference, a terrarium assembly which makes use of a flexible plastic dome mountable on a base to create a hermetically sealed enclosure, the dome being inflatable to assume a desired configuration.
In the collapsible terrarium assembly disclosed in my copending application, a disc-like base structure is provided having a circular ridge formed thereon adjacent its periphery, which ridge is adapted to cooperate with a snap-on coupling ring. Also provided is a dome formed by an open bag of clear flexible plastic material having a circular rim whose diameter is slightly smaller than the diameter of the ridge, the bag having an annular skirt secured thereto and extending outwardly therefrom.
In assembling the terrarium structure, the skirt of the bag is interposed between the coupling ring and the ridge and the ring is snapped onto the ridge, thereby anchoring the bag and hermetically sealing the dome. The bag is provided with a valve having a mouthpiece whereby the dome may be inflated by the user to produce an atmosphere therein which is rich in carbon dioxide.